Folding table leg locking device

ABSTRACT

A folding table leg locking device, for use in securing a table leg rail follower at a fixed position along a horizontallyextending flanged, channel-shaped rail on the underside of a folding table. The device is provided with a spring loaded catch having at least two tongues of unequal length supported on a support pin by brackets formed integrally from the flanges of the channel rail. The brackets including ears for distributing locking impact forces along the rail follower.

United States Patent 1 1 Weiss 1 Nov. 6, 1973 FOLDING TABLE LEG LOCKINGDEVICE [76] Inventor: Samuel Herman Weiss, 2800 W.

Albion, Chicago, Ill. 60645 [22] Filed: Aug. 9, 1971 [21] App]. No.:169,926

[52] US. Cl. 108/133 51] Int. Cl 470 3/08 [58] Field of Search 108/131,132, 133,

' [56] References Cited UNITED STATES PATENTS 2,664,329 12/1953 Kraska108/133 2,672,387 3/1954 Barricks..... 108/133 2,784,042 3/1957 Clapper108/132 Primary ExaminerFrancis K. Zugel Att0meyMerriam, Marshall,Shapiro & Klose [57] ABSTRACT A folding table leg locking device, foruse in securing a table leg rail follower at a fixed position along ahorizontally-extending flanged, channel-shaped rail on the underside ofa folding table. The device is provided with a spring loaded catchhaving at least two tongues of unequal length supported on a support pinby brackets formed integrally from the flanges of the channel rail. Thebrackets including ears for distributing locking impact forces along therail follower.

1 Claim, 9 Drawing Figures Lay l08/l29 FOLDING TABLE LEG LOCKING DEVICEBACKGROUND OF THE INVENTION The present invention relates generally tofolding table leg locking devices and more particularly to an improvedspring loaded device for securing table leg rail followers at a fixedposition along a horizontallyextending flanged channel rail affixed tothe underside of a folding table.

Typical of the leg locking devices presently used in the art are thoseshown in US. Pat. No. 2,672,387. Such devices ordinarily are composed ofa relatively large number of separately assembled elements; are costlyto construct, difficult to install and require constant maintenance.

The construction costs of such devices are high due to the requirementthat certain elements be molded or machined in alternate forms for leftand right side placement. Because of the multiplicity of elements,installation 'is difficult, time consuming and, hence, costly. Becausethe elements are mounted with screws and/ or nuts and bolts, thedevices, once installed, require periodic maintenance in the form oftightening and straightening.

Further, certain aspects of the design of such devices make inherent theprobability of substantial damage to the rail followers held in place bythe devices and also necessitate providing auxiliary blocks or platformsto maintain catch elements in proper position for locking.

BRIEF SUMMARY OF THE INVENTION Locking devices of the present inventionare easily constructed, easily installed, substantiallymaintenance-free, require no auxiliary support elements and yet providesafe, secure fastening of table legs while minimizing wear on railfollowers.

More particularly, locking devices of the invention are used withflanged, channel-shaped rails and include a spring loaded, rail followercatch supported by brackets integrally formed of the flanges of therail. The catch is provided with alternating tongues and slots in amanner allowing secure fastening while eliminating the need for supportblocks or platforms. Ears are integrally formed on the catch supportbrackets and function to distribute locking impact forces which resultin wear and damage to the rail follower.

Further aspects and advantages of the present invention will be apparentfrom the following description of a preferred embodiment thereof,reference being made to the following drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an isometric view of afolding table of the type on which locking devices of the invention maybe used.

FIG. 2 is a fragmentary bottom plan view of the table of FIG. 1, showinga locking device of the invention and having legs in folded position.

FIG. 3 is a sectional view taken along line 33 of FIG. 2.

FIG. 4 is a fragmentary sectional view taken along line 4-4 of FIG. 2.

FIG. 5 is a fragmentary sectional elevational view of a folding tablehaving legs in an unfolded position and secured in place by a lockingdevice of the invention.

FIG. 6 is an isometric view of a locking device of the invention.

FIG. 7 is a sectional view taken along line FIG. 6.

FIG. 8 is a side elevational view of a folding table leg rail followerin a position just prior to being secured by a locking device of theinvention.

FIG. 9 is a side elevational view of a folding table leg rail followerin a secured position in a locking device of the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT FIGS. 1 and 2 show a folding table10 of the type upon which a locking device of the invention, indicatedgenerally at 11, maybe employed. Table 10 has a table top portion 12 ofwood, metal or composite material supportable on pairs of wood or metallegs 13 and 14 when in an unfolded position. Legs 13 and 14 are ofidentical construction. Legs 13, for example, include base elements 13a,13a interconnected to form a U- shape by yoke element 13b. Extendingfrom yoke 13b are mid-sections 13c, 13c which interconnect withtransverse element 13d. Transverse elements 13d, 14d are pivotallyattached to the underside 15 of table top 12 by clamp members 16. Pairsof angled brace members 17, 17 and 18, 18 are individually pivotallyfastened to legs 13 and 14 respectively by bolting elements 19 atpositions intermediate the length of midsections 13c, 13c, 14c, 14c.

Fastened to underside 15 of table top 12 is a horizontally extendingmetal rail 20 having a channel 21 defined by a channel bottom 22 withchannel sides 23, 23 extending generally perpendicularly therefrom (FIG.3). Rail flanges, 24, 24 extend at right angles outwardly from channelsides 22, 22 and generally parallel to channel bottom 22.

Brace member ends 17a, 17a, and 18a, 18a opposite the points ofattachement to table legs, are pivotally attached by rivets 25 tocylindrical rail follower elements 26.

Rail followers 26 are maintained in rolling contact with rail flanges24, 24 by means of L-shaped slide elements 27 which are pivotallyattached to the rail followers by rivets or bolts 25.

In use, as the table legs are folded and unfolded, rail followers 26roll along rail .flanges 24, 24 from an unlocked position near thecenter of the table (FIG. 4) to a locked or secured position at lockingdevice 11 (FIG. 5).

Referring to FIGS. 6 and 7 locking device 11 is provided with a railfollower catch 28. Catch 28 includes a longitudinally-extendingcatchbody portion 29 from one end of which a first tongue element 30 extendsgenerally perpendicularly. Inward of and adjacent to tongue 30 is acatch slot 31. Inward of and adjacent to slot 31 is a second tongueelement 32 extending generally perpendicularly from catch body 29 adistance less than that to which tongue 30 extends. Inward of andadjacent to tongue 32 is another catch body slot 33. Catch body 29 isprovided with an aperture 34 for supporting catch 28 on rail 20.

Locking device 11 is further provided with a pair of catch supportingbrackets 35, 35 formed integrally from rail flanges 24 extendinggenerally perpendicunected therewith. Each bracket 35 is preferrablyprovided with an ear 39, adjacent slot 38, for distributing impactforces, generated upon locking of a rail follower, along a relativelylarger surface of the rail follower and thus reducing wear on thefollower.

A spring element 40 is provided around pin 37 and positioned in such amanner as to urge tongue 30 at all times toward contact with channelbottom 22.

Catch 28 is provided with a laterally extending tab element 41 for usein manually raising tongues 30 and 32 away from channel 21 to release alocked rail follower 26 from a secured position.

Use of expensive catch support pins having a varying diameter is avoidedby providing a hollow support pin 37, retained in position aftermounting on a catch 28, by a rivet 42 at each end as shown in FIG. 7.

Operation of the locking device of the invention is best illustratedwith reference to FIGS. 4, 5, 8 and 9.

When table legs 13 are in a folded position (FIG. 4), locking device 11has the tip 30a of tongue 30 urged into contact with channel bottom 22by spring 40. Rail follower 26 is at a position along channel rail 20relatively remote from locking device 11.

As legs 13 are moved downward and away from the underside 15 of tabletop 12 toward a vertical position, rail follower 26 slides along railflanges 24, 24 until follower 26 contacts the curved forward edge 30b oftongue 30. Due to the curvature of edge 30b, continued application offorce on legs 13 will cause rail follower 26 to displace tongue 30 awayfrom channel bottom 22 (FIG. 8). Once rail follower 26 has moved pasttongue tip 30a, spring 40 moves tip 300 toward channel bottom 22,securing rail follower 26 in slot 31 and catch 28 presses follower 26against rail flanges 24, 24 (FIG. 5). Slot 31 thus functions as a safetyslot to insure that legs 13 will not collapse if the legs are not movedto a completely vertical position in the unfolding procedure.

Further application of force on legs 13 causes rail follower 26 tocontact curved edge 32b of tongue 32, displacing the tongue away fromchannel 21. As rail follower 26 is moved past tip 32a of tongue 32, tip32a is moved toward channel 21 by action of spring 40, engaging railfollower 26 in tongue slot 33 and bracket slots 38, 38 thus securinglegs 13 in a locked verticle position (FIG. 9).

When legs 13 are to be collapsed from the vertical position, tab element41 is depressed toward table underside 15, freeing rail follower 26 fromengagement in tongue slot 33, and thus permitting movement of follower26 along rail away from locking device 11.

Obviously, many modifications and variations of the above-describedinvention may be made without departing from the spirit and scopethereof. Therefore, only such limitations as are indicated in theappended claims should be placed thereon.

What is claimed is:

1. In a folding table-leg locking device for use in securing a table legrail-follower at a fixed position along a horizontally-extending,channel-shaped flanged rail on the underside ofa table, the improvementcomprismg:

spring loaded, rail-follower catching means, said catching meansincluding:

a longitudinally extending catch body;

a first unitary tongue element at one end of said catch body andextending generally perpendicularly therefrom;

a first slot in said catch body for engaging said railfollower, saidfirst slot being located inward of said first tongue and adjacentthereto;

a second unitary tongue element, inward of said first slot and adjacentthereto;

a second slot in said catch body for engaging said rail follower, saidsecond slot being located inward of said second tongue element andadjacent thereto: and

a catch support pin aperture, inward of said second slot;

a pair of catch supporting bracket means each formed integrally of arespective flange on said rail and extending generally perpendicularlythereto: a bracket body on each of said catch supporting bracket means;

slot means in each bracket body for securing a rail followercooperatively with said second slot of said catch body;

a catch support pin aperture in each bracket body;

a catch support pin extending through the support pin apertures of saidcatch body and said catch support bracket bodies;

spring means, cooperative with said catching means, said bracket meansand said catch support pin, for urging said first tongue element of saidcatch body toward the channel of said rail;

and means for distributing locking impact force along the length of therail follower;

said impact-distributing means comprising ear means formed integrally ofeach bracket body adjacent to the bracket slot means thereof andextending from said bracket body in a direction transverse to thedirection of movement of said rail follower;

the dimension of said ear means in said transverse direction beingrelatively large compared to the thickness of said bracket body at saidslot.

1. In a folding table-leg locking device for use in securing a table legrail-follower at a fixed position along a horizontallyextending,channel-shaped flanged rail on the underside of a table, the improvementcomprising: spring loaded, rail-follower catching means, said catchingmeans including: a longitudinally extending catch body; a first unitarytongue element at one end of said catch body and extending generallyperpendicularly therefrom; a first slot in said catch body for engagingsaid railfollower, said first slot being located inward of said firsttongue and adjacent thereto; a second unitary tongue element, inward ofsaid first slot and adjacent thereto; a second slot in said catch bodyfor engaging said rail follower, said second slot being located inwardof said second tongue element and adjacent thereto: and a catch supportpin aperture, inward of said second slot; a pair of catch supportingbracket means each formed integrally of a respective flange on said railand extending generally perpendicularly thereto: a bracket body on eachof said catch supporting bracket means; slot means in each bracket bodyfor securing a rail follower cooperatively with said second slot of saidcatch body; a catch support pin aperture in each bracket body; a catchsupport pin extending through the support pin apertures of said catchbody and said catch support bracket bodies; spring means, cooperativewith said catching means, said bracket means and said catch support pin,for urging said first tongue element of said catch body toward thechannel of said rail; and means for Distributing locking impact forcealong the length of the rail follower; said impact-distributing meanscomprising ear means formed integrally of each bracket body adjacent tothe bracket slot means thereof and extending from said bracket body in adirection transverse to the direction of movement of said rail follower;the dimension of said ear means in said transverse direction beingrelatively large compared to the thickness of said bracket body at saidslot.